Numerous power-engineering applications require the measurement of high electric currents. For this purpose, a magnetic field induced about an electric conductor by the electric current may be detected and evaluated. A detected magnetic field of this kind may provide information on the electric current flowing through the conductor. For this purpose, it is also possible to guide an electrical conductor through an annular so-called flux concentrator. Such a flux concentrator may be made of a ferromagnetic material; as a result of which, the magnetic field lines concentrate around the current-carrying conductor in this flux concentrator. The magnetic field in this flux concentrator can be detected by a magnetic-field sensor, such as a Hall sensor, in a slot in the flux concentrator. However, such flux concentrators made of ferromagnetic or ferrimagnetic materials require a relatively high sensor weight. In addition, measuring errors can also occur as a result of magnetic hysteresis.